Apparatus for controlling Anti lock Brake System of ESC integrated brake system and method thereof

Abstract

An apparatus for controlling an ABS of an ESC integrated brake system and a method thereof. The apparatus includes a main master cylinder generating hydraulic brake pressure through a piston that is moved forward/backward by an actuator that is operated when a brake pedal of a vehicle is pressed down; and a controller controlling forward/backward movement direction change of the piston by controlling a driving current that is applied to the actuator by determining whether a direction change condition according the control state of wheel pressure is satisfied, when a brake mode of the vehicle is an ABS mode and the piston has reached a predetermined direction change position for forward/backward movement direction change.

What is claimed is: 
     
       1. An apparatus for controlling an Anti-lock Brake System (ABS) of an Electronic Stability Control (ESC) integrated brake system, the apparatus comprising:
 a main master cylinder generating hydraulic brake pressure through a piston that is moved forward/backward by an actuator that is operated when a vehicle is in a braking status; and 
 a controller configured to: 
 determine whether a direction change condition according to a control state of wheel pressure is satisfied when a brake mode of the vehicle is an ABS mode and the piston has reached a predetermined direction change position for forward/backward movement direction change, and 
 perform forward/backward movement direction change of the piston by controlling a driving current that is applied to the actuator upon determining that the direction change condition according to the control state of wheel pressure is satisfied, 
 wherein the controller determines whether the direction change condition is satisfied by checking open/close states of inlet valves that connect/disconnect hydraulic brake pressure that is supplied to each wheel cylinder of the vehicle. 
 
     
     
       2. The apparatus of  claim 1 , wherein the direction change condition according to the control state of wheel pressure is satisfied when wheel pressure for front wheels and rear wheels is maintained or in a pressure-decreasing control state, or when wheel pressure for the front wheels is maintained or in a pressure-decreasing control state and wheel pressure for the rear wheels is in a pressure-increasing control state. 
     
     
       3. An apparatus for controlling an Anti-lock Brake System (ABS) of an Electronic Stability Control (ESC) integrated brake system, the apparatus comprising:
 a main master cylinder generating hydraulic brake pressure through a piston that is moved forward/backward by an actuator that is operated when a vehicle is in a braking status; and 
 a controller controlling forward/backward movement direction change of the piston by controlling a driving current that is applied to the actuator by determining whether a direction change condition according to a control state of wheel pressure is satisfied, when a brake mode of the vehicle is an ABS mode and the piston has reached a predetermined direction change position for forward/backward movement direction change, 
 wherein the direction change position comprises an upper limit direction change position set as a position under a threshold upper limit position of the piston, and a lower limit direction change position sets as a position over a threshold lower limit position of the piston. 
 
     
     
       4. The apparatus of  claim 3 , wherein the controller performs forward/backward movement direction change of the piston by controlling a driving current, which linearly increases/decreases within a range having a value lower than a reference driving current, to be applied to the actuator,
 wherein the reference driving current is a current that is applied to the actuator to generate torque required for forward/backward movement direction change of the piston at the threshold upper limit position or the threshold lower limit position. 
 
     
     
       5. A method of controlling an Anti-lock Brake System (ABS) of an Electronic Stability Control (ESC) integrated brake system, the method comprising:
 a step in which a controller determines whether a brake mode of a vehicle is an ABS mode; 
 a step in which when the brake mode of a vehicle is the ABS mode, the controller determines whether a piston of a main master cylinder has reached a predetermined direction change position for forward/backward movement direction change, in which the main master cylinder generates hydraulic brake pressure through the piston that is moved forward/backward by an actuator that is operated when a vehicle is in a braking status; 
 a step in which when the piston has reached the direction change position, the controller determines whether a direction change condition according to a control state of wheel pressure is satisfied; and 
 a step in which when the direction change condition is satisfied, the controller performs forward/backward movement direction change of the piston by controlling a driving current that is applied to the actuator upon determining that the direction change condition according to the control state of wheel pressure is satisfied, 
 wherein in the step in which the controller determines whether a direction change condition is satisfied, the controller determines whether the direction change condition is satisfied by checking open/close states of inlet valves that connect/disconnect hydraulic brake pressure that is supplied to each wheel cylinder of the vehicle. 
 
     
     
       6. The method of  claim 5 , wherein the direction change condition according to the control state of wheel pressure is satisfied when wheel pressure for front wheels and rear wheels is maintained or in a pressure-decreasing control state, or when wheel pressure for the front wheels is maintained or in a pressure-decreasing control state and wheel pressure for the rear wheels is in a pressure-increasing control state. 
     
     
       7. The method of  claim 5 , wherein the direction change position comprises an upper limit direction change position set as a position under a threshold upper limit position of the piston, and a lower limit direction change position set as a position over a threshold lower limit position of the piston. 
     
     
       8. The method of  claim 7 , wherein in the step in which the controller performs forward/backward movement direction change of the piston, the controller performs forward/backward movement direction change of the piston by controlling the driving current, which linearly increases/decreases within a range having a value lower than a reference driving current, to be applied to the actuator,
 wherein the reference driving current is a current that is applied to the actuator to generate torque required for forward/backward movement direction change of the piston at the threshold upper limit position or the threshold lower limit position.